Media for Dairy Industry

Milk is sterile at secretion in the udder but is contaminated by bacteria even before it leaves the udder. In normal case the bacteria at this point are harmless and few in number but milk is a good growth nutrient for them. So the control for pathogens is really important, specially in raw milk products but bateria are used as well starter cultures in the production of cultured dairy products such as yogurt.

Spoiling bacteria (degradation of protein, carbohydrates and fats): Most psychrotrophs are destroyed by pasteurization temperatures, however, some like Pseudomonas fluorescens, Pseudomonas fragi can produce proteolytic and lipolytic extracellular enzymes which are heat stable and capable of causing spoilage. Some species and strains of Bacillus, Clostridium, Corynebacterium, Arthrobacter, Lactobacillus, Microbacterium, Micrococcus , and Streptococcus can survive pasteurization and grow at refrigeration temperatures